Its been such a long time ! This is from a previous post !
Yes, For the first time,they send you a verification txt code to the phone on file.
I installed and registered my Yubico 5 NFC today !
1. I went to Yubico's website and verified that it was genuine,
by inserting it in the USB ,soon after the Yubico ok it.
2. I went to B Of America site and had to get a code and use my pin to my debit card ,to initiate the verification process ! I followed the next prompt.
3. I pressed the button on the key and a screen came up ,
Security key was successfully added